Background gamma terrestrial dose rate in Nigerian functional coal mines.
D000398:Air Pollution, Radioactive; D001417:Background Radiation; D002138:Calibration; D003032:Coal Mining; D005720:Gamma Rays; D009549:Nigeria; D011886:Radon; D012990:Soil Pollutants, Radioactive
D012990:Soil Pollutants, Radioactive; D011886:Radon